Trends in Remedy Selection, Optimization and Green Remediation
Carlos Pachon, U.S. EPA Office of Superfund Remediation & Technology Innovation
Washington DC, U.S.A.
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PhytoSUDOE Final Conference.October 11th 2018
Vitoria-Gasteiz, Spain
PhytoSUDOE Final Conference.October 11th 2018
Vitoria-Gasteiz, Spain
Agenda
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a) Recent trends in the selection of remedies in the Superfund Program
b) High level insights on the selection of phytoremediation technologies in Superfund
c) Green remediation ≠ phytoremediation
d) Lessons learned and best practices in the implementation of remedies
e) Three short field cases summarizing a-c, with a focus on phyto
f) Discussion
Types of Contaminated Site Remedies
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♦ Treatment (“reduction of toxicity, mobility or volume”)» Ex situ (above ground)
› Such as pump and treat of groundwater with solvents» In situ (below ground)
› Such as soil vapor extraction to remove solvents from soil or chemical treatment to destroy solvents in groundwater
♦ Containment» Capping of soil or landfills
♦ Off-site Disposal» Excavation and offsite disposal in a permitted landfill
♦ Others» Monitored Natural Attenuation» Alternative Water Supply» Institutional Controls
Superfund Law Established a Preference for Treatment in
Remedy Selection
Remedy Decisions in the Superfund Program“Records of Decision” per Year (FY 1981–2014)
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1338 Listed sites412 Deleted sites
Superfund “Source” Remedy Selection TrendsDecision Documents with the Five Main Remedy Types (1986-2014)
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0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
1986; 60%1987; 61%
1988; 78%1989; 76%
1990; 65%
1991; 76%
1992; 70%1993; 68%
1994; 51%1995; 54%1996; 56%
1997; 41%
1998; 52%1999; 50%
2000; 43%2001; 41%
2002; 63%
2003; 55%
2004; 39%
2005; 52%
2006; 41%
2007; 33%2008; 35%
2009; 47%
2010; 33%2011; 38%
44% 39%
55%
63%
37%39%
47%
40%
50%
74%73%77%
2% 3% 3%
Treatment Containment (on-site) Disposal (off-site)Institutional Controls MNA/MNR/EMNR
Perc
enta
ge o
f Sou
rce
Dec
isio
n Do
cum
ents
Superfund Groundwater Remedy Selection Trends (FY 1986-2014)
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1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
20140%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1986; 3%1987; 4%1988; 2%
1989; 13%
1990; 8%1991; 10%
1992; 13%1993; 8%
1994; 12%1995; 14%
1996; 11%1997; 16%
1998; 20%1999; 17%
2000; 23%2001; 26%
2002; 29%2003; 28%2004; 28%2005; 27%
2006; 35%
2007; 30%2008; 32%
2009; 39%2010; 39%2011; 38%
42%
58%
53%
1986; 69%
1987; 77%1988; 82%
1989; 79%1990; 81%
1991; 85%
1992; 77%
1993; 71%1994; 72%
1995; 60%1996; 59%
1997; 43%
1998; 36%
1999; 50%2000; 50%
2001; 44%
2002; 53%
2003; 33%2004; 35%
2005; 41%
2006; 24%2007; 28%
2008; 33%
2009; 26%
2010; 18%
2011; 23%
26% 26%
17%
1986; 15%1987; 15%
1988; 22%
1989; 27%
1990; 41%1991; 42%
1992; 54%1993; 54%
1994; 67%
1995; 61%1996; 64%1997; 65%
1998; 73%
1999; 68%
2000; 61%
2001; 67%
2002; 61%
2003; 69%2004; 66%
2005; 78%
2006; 85%2007; 80%
2008; 86%
2009; 82%
2010; 86%2011; 85%84%
68%
83%
1986; 5%1987; 4%1988; 8%
1989; 2%1990; 4%1991; 5%
1992; 7%
1993; 12%
1994; 17%
1995; 29%
1996; 20%
1997; 27%
1998; 46%1999; 41%
2000; 29%2001; 33%
2002; 14%
2003; 26%
2004; 40%
2005; 45%
2006; 38%
2007; 32%2008; 30%
2009; 16%
2010; 35%2011; 31%
37%
28%
34%
1986; 10%
1987; 17%
1988; 5%1989; 4%1990; 2%1991; 2%1992; 4%
1993; 2%1994; 3%1995; 4%1996; 3%1997; 3%1998; 3%1999; 5%2000; 3%2001; 4%2002; 8%
2003; 0%2004; 0%2005; 3%2006; 4%2007; 5%
2008; 2%2009; 3%2010; 1%
2011; 7%
0%
4% 6%
1986; 33%1987; 31%
1988; 18%1989; 21%
1990; 13%1991; 13%1992; 10%
1993; 13%1994; 13%
1995; 8%1996; 7%1997; 11%1998; 9%
1999; 12%
2000; 4%
2001; 12%
2002; 3%2003; 5%2004; 9%2005; 9%2006; 7%
2007; 5%
2008; 14%
2009; 7%2010; 9%2011; 8%5% 6% 8%
In Situ Treatment P&T Institutional ControlsMNA VEB Alternative Water Supply
Perc
enta
ge o
f Gro
undw
ater
Dec
isio
n Do
cum
ents
Treatment at Superfund Sites (FY 1982-2014)
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Treatment of Source; 275; 18%
Treatment of Both Source and Groundwater; 649; 42%
Treatment of Groundwater; 272; 18%
On-site Containment or Off-site Disposal of a Source; 190; 12%ICs, MNA or MNR for a Source; 24; 2%
Containment, ICs, MNA or Alternative Water Supply for Groundwater; 37; 2%No Action or No Further Action Only; 93; 6%
AWS = alternative water supplyMNA = monitored natural attenuationMNR = monitored natural recoveryNA = No actionNFA = No Further Action
Non-Treatment, NA or NFA– 344 Sites (22%)
Treatment – 1,196 Sites (78%)
Source Treatment Only; 14; 7%Source Treatment and ICs; 5; 3%
Source Treatment and On-site Containment or Off-site Disposal; 18; 10%
Source Treatment, On-site Containment or Off-site Disposal and ICs; 48; 26%
Source Treatment, On-site Containment or Off-site Disposal, ICs, and MNR or EMNR; 1; 1%Source MNR or EMNR Only; 1; 1%Source ICs Only; 37; 20%
Source ICs and MNR or EMNR; 1; 1%Source On-site Containment or Off-site Disposal Only; 15; 8%
Source On-site Containment or Off-site Disposal and ICs; 46; 24%
Source On-site Containment or Off-site Disposal, ICs, and MNR or EMNR; 2; 1%
EMNR = enhanced monitored natural recoveryIC = institutional controlMNR = monitored natural recovery
Combinations of Recent Source Remedies (FY 2012-2014)
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Treatment - 86 (46%)
Non-Treatment -102 (54%)
P&T, Source Treatment and On-s ite Containment or Off-site Disposal; 507; 61%
P&T and Source Treatment; 80; 10%P&T with Source On-site Containment or Off-site Disposal; 129; 15%
P&T and In Situ Treatment for Groundwater; 19; 2%
P&T and MNA for Groundwater; 18; 2%
P&T, In Situ Treatment and MNA for Groundwater; 7; 1%
P&T only for Groundwater; 74; 9%
Summary of 834 Groundwater P&T Remedies
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P&T with Source Control - 71686%
P&T with no Source Control - 11814%
MNA = monitored natural attenuationP&T = pump and treat
Source Remedies Selected in Recent Decision Documents 2012-2014 Source Decision Documents = 188
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Phytotechnology Applications: A Broader Window
11https://clu-in.org/download/remed/phytotechnologies-factsheet.pdf
Source Remedies Selected in Recent Decision Documents (FY 2012-2014)Source Decision Documents = 188
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Source Remedies Selected in Recent Decision Documents 2012-2014 (cont’d) Source Decision Documents = 188
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Groundwater Remedies Selected in Recent Decision Documents 2012–2014 Groundwater Decision Documents = 160
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Broader Perspectives on the use of plants at Contaminated Sites Cleanup Projects
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♦ There is a continuum in the degree to which plants contribute to the remediation of a contaminated site» Core treatment (“reduction of toxicity, mobility or volume”) of the
contaminated media, traditional concept of phytoremediation» Non-treatment, but critical role, in a combined remedy (for
example hydraulic control)» Supplemental functions, such as storm water management
♦ In any of the above roles, plants are an important providers of ecosystem services at remediation projects
♦ Climate change resilience in remedies is driving the incorporation of plant centered technologies, such as narural drainage systems
Field Example 1: National Fireworks Superfund Site, OU2
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♦ Site Background» 260-acre site in Cordova, Tennessee.» Manufactured munitions for the U.S. Army and Navy.» In 1986 the site was redeveloped as an industrial park» A time-critical removal action conducted in 2010-2011 removed
contaminated soil, debris and live pin flares. » Site is being addressed under a Superfund Alternative Approach
Agreement♦ Operable Unit 2
» Interim remedy addresses groundwater and subsurface soil contamination on the north-central portion of the site.
» Primary contaminants include tetrachloroethene (PCE) and its degradation products.
Field Example 1: National Fireworks Superfund Site, OU2
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Source Area C Requiring Further Assessment
Plume E
Source C
Monitoring Well Sample LocationProposed Monitoring Well LocationProposed Surface Water Sample LocationPhytoremediation Barrier (To Be Finalized in Remedial Design)Source/Plume Area (To Be Finalized in Remedial Design)
Source D
Field Example 1: National Fireworks Superfund Site, OU2
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♦ Remedial Approach» Install trees within the footprint of Plume C (100 trees),
Plume D (130 trees) and Plume E (100 trees)» Promote aggressive root development to depths up to 30
feet or more by developing borehole to the depth desired, inserting a sleeve or liner to direct root growth, then backfilling the borehole with soil and planting the selected tree species.
♦ Treatment Mechanism» Most of the absorbed VOCs will be transferred in the water
uptake to the leaves through the xylem (the primary vascular tissue of trees).
» Dechlorination of the chlorinated VOCs occurs in both the root zone and in the leaves.
Field Example 1: National Fireworks Superfund Site, OU2
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♦ Current status» Site is currently in the remedial action phase.» Monitoring of the surface water and groundwater will
continue to evaluate the effectiveness of the remedy.» A final remedy will be selected to address additional source
areas and Plume A and Plume B remediation.♦ Phytoremediation is not typically the primary
treatment remedy but can be used effectively as a primary treatment or part of an overall strategy.
Field Example 2: Mattiace Petrochemical Co., Inc., Superfund Site
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♦ Site Background» 2.5-acre site in Glen Cove, New York» Chemical distribution facility from 1960s until 1987» Drum cleaning activities until 1982» Removal action in 1988 to remove 100,000 gallons of
hazardous liquids♦ Remedial Approach
» P&T, SVE and LNAPL recovery selected in 1990/1991» Optimization performed in 2000 provided suggestions for
improvement of existing systems and recommended further delineation of LNAPL
» Remedial action amended in 2014 to address newly identified LNAPL plume
Field Example 2: Mattiace Petrochemical Co., Inc., Superfund Site
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♦ Amended Remedy» Remedy changed from P&T to combined remedies:
› ISTT› Bioventing (aerobic)› Enhanced reductive bioremediation (anaerobic)› Partial vertical engineered barrier (VEB) and
phytoremediation (for hydraulic control)» Hydraulic control via phytoremediation to address water level
increase behind the partial VEB» Phytoremediation may extract some VOC contaminants,
although hydraulic control is the main purpose» Phytoremediation will contribute to meeting remedial action
objectives» P&T wells can be restarted if necessary
Field Example 2: Mattiace Petrochemical Co., Inc., Superfund Site
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Partial VEB (purple line)Phytoremediation conceptual designWillow, cottonwood tree (yellow triangle)
Poplar tree (green dot)
Field Example 2: Mattiace Petrochemical Co., Inc., Superfund Site
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♦ Current Status» In remedial design phase» VEB construction completed Sept 2017 (purple line shown
on next slide)» Conceptual site design will include a proprietary engineered
approach to promote aggressive root development in the targeted horizon
» Tree species chosen based on robustness, ability to extract large amounts of water, rapid growth potential and water-seeking root growth› Willow and cottonwood trees (yellow triangles) › Poplar trees (green dots)
Field Example 3: Moffett Field Phyto-barrier with Endophyte Inoculated Hybrid Poplars
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♦ MEW Superfund Area (includes 4 NPL sites – Fairchild Semiconductor, Intel, Raytheon, and portions of NAS Moffett Field). A high profile site in Silicon Valley, CA
♦ Primarily TCE groundwater contamination (+2km plume). 1989 GW and Soil remedy: P&T, slurry wall, SVE, excavation. 2010 - Vapor Intrusion remedy.
♦ 2008 Optimization report recommends treatability study of additional technologies, including phyto
♦ 2013 Feasibility study chosen using phytoremediation to address shallow plume
♦ 2015-2018 treatability study initiated by NASA using phytotechnology to address shallow TCE plume.
♦ EPA anticipates incorporating Phyto findings in EPA 2019 Shallow Zone FFS.
Field Example 3: Moffett Field Phyto-barrier with Endophyte Inoculated Hybrid Poplars
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♦ Project goal: Enhanced degradation of groundwater VOCs at a Superfund site using endophyte-assisted Poplar tree phytoremediation
♦ Initial findings after 4 growing seasons: Inoculated trees show improved growth rates & greater indications of TCE breakdown
♦ Findings published in Environmental Science & Technology, 2017
2014
2018
Summary of Phytoremediation Field Examples
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♦ Phyto is rarely the prime treatment remedy, but in certain situations it can meet cleanup goal
♦ We continuously evaluate remedies and adapt as we learn. At field case 2 & 3 we transitioned from P&T to a combined remedy approach, with phytotechnologies helping in hydraulic control
♦ Innovations continue, particularly for volatiles, such as use of endophyte inoculated trees for increased phytotoxicity resistance and enhanced biodegradation of TCE
♦ Use of phytotechnologies to treat metals is a continuing challenge
♦ There is a broad continuum of opportunities in the use of plants to treat and restore contaminated sites
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Green Remediation: Meeting Cleanup Objectives With a Smaller Environmental Footprint
Green Remediation: Meeting Cleanup Objectives With a Smaller Environmental Footprint
Myths, Truths & Tools
Greener Cleanups Are…. NOT just about GHG
NOT about the greenest technology
The same as green remediation
Integral to more sustainable cleanups
Recommended Project Level Tool: ASTM Standard Guide for Greener Cleanups
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https://www.epa.gov/greenercleanups
Examples of Best Management PracticesExamples of Best Management Practices
http://clu-in.org/greenremediation/profiles
Recycled concrete for erosion control
Wetlands for stormwater & habitat
A mobile solar system to power tools
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EPA’s Working Definition of Optimization
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Systematic site review by a teamof independent technical experts,
at any phase of a cleanup process, to identify opportunities to improve remedy protectiveness, effectiveness
and cost efficiency, and to facilitate progress toward site completion.
EPA’s National Optimization Program revolves around third-party evaluations
P&T Selection for Decision Documents with Groundwater Remedies (FY 1985-1995)
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400% 500% 600% 700% 800% 900% 1000%1100%1200%1300%1400%0
20
40
60
80
100
120
140
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
27
4237
7666
92
115
74 76 74
62
79%
69%
77%82%
79% 81%85%
77%71% 72%
60%
Num
ber o
f Gro
undw
ater
Dec
isio
n D
ocum
ents
Perc
enta
ge o
f Gro
undw
ater
Dec
isio
n D
ocum
ents
Key Optimization Components and Superfund Pipeline Activities
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Early Efforts
Moving U
pstream
Number of Implemented Tools and Techniques Total Number of Optimization Events = 80
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0
10
20
30
40
50
6054
48
31 29
13 126
Num
ber o
f Opti
miz
ation
Eve
nts
68%
60%
39%36%
16% 15%
8%
Summary Conclusions
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♦ The remediation services sector provides a broad suite of options to remediate contaminated sites
♦ Technologies are often use in combination to address different contaminants and media at a site
♦ Phytoremediation is rarely the main treatment remedy, but often is a part of the solution at many sites
♦ Green remediation helps us build and operate any chosen remedy with a lower environmental footprint
♦ Optimization allows us to capture lessons learned and build them into existing or new treatment systems
